A New Look at the Relation Between Discrepancy and Change

194 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.In persuasive communication theory and research discrepancy is traditionally defined in terms of the (absolute) difference between initial position of the receiver and the position advocated by the source of a message. Three experiments were performed in which the persuasive communication process was studied at the belief level. An interactive computer system was used to manipulate the receivers' initial beliefs.First, based on existing persuasive communication models it was predicted that--holding other relevant factors like the source, the receiver, the topic of the message, and the extremity of the receivers' initial positions constant--equal levels of discrepancy should result in equal amounts of change. This hypothesis was tested in Experiment I by manipulating the receivers' initial beliefs(Pl) at scale positions adjacent to the midpoint of the scale. For equal levels of discrepancy less agreement with the source and less change was obtained if the source belief(Ps) fell on the opposite side of the midpoint than if Ps fell on the same side of the midpoint as Pl. Experiment II indicated that this effect cannot be attributed to the fact that the midpoint of the scale serves as an anchor, as predicted from social judgment theory. Instead, Experiment III showed that the decrease in change in the different side condition is contingent upon the receivers' awareness of qualitative differences between Pl and Ps.Second, five quantitative persuasive communication models were fitted to the data of Experiment II and III. In both cases the best overall fit was obtained for the linear model C = b.D (where C = change, D = discrepancy, and b is a parameter to be estimated). It was further shown in Experiment II that despite a significant increase in the receivers' certainty, extremity of initial position did not affect change. This made it possible to combine equally discrepant messages in order to study the relation between discrepancy and change in greater detail. In conflict with existing theory and research in the persuasive communication area, it was possible to identify three subgroups of receivers who either showed a negatively accelerated, a (near) linear, or a positively accelerated relation between discrepancy and change. This finding was replicated in Experiment III.It has repeatedly been shown that a person's attitudes, intentions, and behaviors are ultimately determined by his or her beliefs. Therefore, the present findings raise serious questions concerning the validity of the assumptions made in traditional persuasive communication research. A framework is proposed to deal with some of these issues in terms of the qualitative "regions" of a belief dimension.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD